OPT: maths: allows thr to be float
OPT: maths: allows thr to be float

Former-commit-id: e062cf4bc7d566899147b0f1ed6efeef28351058 [formerly 02824ddf298e74e8735ed7dbb047fa2d406a899e]
Former-commit-id: fd51fe2a0c6c7d28377489da769e921c8a2311cb
Former-commit-id: 09d7b0a6b1dc3d6a5c41675793c19b46e119dc78
neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox